@unpublished{repository50077,
            note = {Unpublished},
           title = {Surat Permohonan Pembicara SMA Yappenda},
       publisher = {Universitas Muhammadiyah Prof. DR. HAMKA},
             url = {http://repository.uhamka.ac.id/id/eprint/50077/},
          author = {Ahmad, Mubarak}
}